How many 2-inch by 3-inch rectangular tiles are required to tile this

Question

https://gmatclub.com/forum/download/file.php?id=29094 How many 2-inch by 3-inch rectangular tiles are required to tile this shaded region? A. Less than 10 B. 10—100 C. 101—1,000 D. 1,001—1,500 E. 1,500+ 2016-01-24_1704.png

chetan2u · Accepted Answer

hi answer is E itself

there is a 6'*12' garden with a 2'*3' patch..
Q is - How many 2"*3" tiles can be placed and not 2'*3'

convert all feet into inches as we arelooking into tiles which are in inches

1) so total area of garden = 6*12*12*12
2) Area of patch = 3’*2’=(3*12*2*12)”

Hence, shaded region = 12*12*12*6 - 12*12*3*2 = 12*12(6*12-2*3) = 12*12*2*3(12-1)..
 no of 2"*3" tiles required = \frac{12*12*12*2*3*11}{2*3} = 12*12*11= 1584 > 1500  
so ans is 1500+
E

manohar0265 · Answer

12*6/3*2=12
As it has a tile already .it requires 11 tiles

EMPOWERgmatRichC · Answer

Hi All,

These types of 'spacial relations' questions are rare on Test Day (chances are that you will NOT see any), but there is often a 'twist' to the question - involving placing the 'tiles' in a specific way. This question doesn't actually have a twist though (the numbers 2 and 3 are BOTH factors of 6 and 12, so you can orient the 'tiles' up-down or left-right and fill the space.

Since the total area is (6)(12) = 72 and the area of each tile is (2)(3) = 6, we know that the number of tiles needed to fill the space is 72/6 = 12 total tiles.

Final Answer:  B

GMAT assassins aren't born, they're made,
Rich

vivekkumar987 · Answer

This kind of sum I prefer graphical approach to avoid mistake

two orientations possible

Please refer the attachment for figure

in both 6*2 orientation or 3*4 orientation , there will be 12 tiles

chetan2u · Answer

Hi,
Answer is E itself, most have not read/understood the Q correctly..

there is a 6'*12' garden with a 2'*3' patch..
How many  2"*3" tiles can be placed and not 2'*3' 
   So VERY IMPORTANT TO READ Q PROPERLY

ans  \frac{{6*12*12*12}}{{2*3}}- \frac{{2*12*3*12}}{{2*3}}=12*12*12-12*12= 11*12*12 , which is 1000+ and hence E

chetan2u · Answer

Bunuel , 
E is ok..
people have not read Q properly

Spikey243 · Answer

damn that was tricky :D

dina98 · Answer

total number of tiles is 1584. Convert 12 ft x 6 ft to inches and then find out how many tiles can fit in the shaded region.

sabxu1 · Answer

so what is the answer E or? why is E ok im so confused

InstantMBA · Answer

The international symbols for feet and inches are  ft  and  in , respectively. But sometimes in the USA, people use the prime and double prime symbols to represent feet and inches, respectively. The OP did not include a definition of prime and double prime. IMHO, it's quite unlikely people outside the USA may be aware that the single prime is not an inch, but a foot. I seriously doubt the GMAT exam contains a question  exactly  as specified in the OP.

rhine29388 · Answer

Apologies for finding a doubt with figure
nowhere in the figure it is showing that the rectangle is 12 feet * 6 feet 
or are we supposed to assume 12' as 12 feet?

rhine29388 · Answer

Apologies for finding a doubt with figure
nowhere in the figure it is showing that the rectangle is 12 feet * 6 feet 
or are we supposed to assume 12' as 12 feet?

msk0657 · Answer

Bunuel, 
Can you give us your solution too..

gvij2017 · Answer

" stands for Inches 
' stands for feet .

And this question is god to know how much you are attentive about units. 
(12*12*6*12)/(3*2) > 1500

minatminat · Answer

This is tricky!!! 
" = Inch, ' = ft ! 
1 ft = 12 inch

frankgraves · Answer

I am not from the US, I am not aware that ' is ft and '' is inch.
Do we really need to know this for GMAT?

MBAB123 · Answer

frankgraves , probably not. But for me, the takeaway was not that ' is ft and " is inch. I knew it before seeing this question, but did not pay attention to this while solving this question and got the answer wrong.  Bunuel  this was awesome even if it's not likely to be tested on the GMAT.

Jaya6 · Answer

Hey, can you explain the shaded region and the fraction thereafter? should 3'2' not necessarily be 3'*12*2'*12?
and the unshaded portion as 6*12*12*12/ 3'*12*2'*12?

chetan2u · Answer

The unshaded portion is 3’*2’=3*12*2*12.

While, the shaded will become total-unshaded. => 6*12*12*12-3*12*2*12

How many 2-inch by 3-inch rectangular tiles are required to tile this

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How many 2-inch by 3-inch rectangular tiles are required to tile this

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